Independent measures design ANOVA; repeated-measures design

4 Four separate experiments investigated the effect of three postulated amnestic agents on memory for a simple rote learning task. The task consisted of the learning of a list of 80 monosyllabic words presented to the subject at the rate of 1 per second, via a tachistoscope. The list was presented 10 times. At the end of the final trial, the subject was asked to write down as many words as could be remembered in any order. The three drugs were A1: an antibiotic, A2: an anticonvulsant, A3: a cholinergic blocker. As a control, a fourth treatment condition was introduced, namely A4: saline. All drugs were administered orally, and training began 30 min. after administration of the drugs. On the basis of theory, it was expected that drug A4 would have no effect on memory, while drugs A1, and A2 should retard memory, although the relative sizes of their effects could not be predicted. Twenty-eight subjects were selected at random and assigned equally and randomly to the four treatment conditions.

For this question you will be assigned data from one of these experiments on the basis of the first letter of your last name.
If your last name begins with the letters A-E use data from Experiment 1
If your last name begins with the letters F-K use data from Experiment 2
If your last name begins with the letters L-R use data from Experiment 3
If your last name begins with the letters S-Z use data from Experiment 4

(a) Analyze your data set with an independent measures design ANOVA. On a standard answer sheet, state clearly the null and alternative hypotheses (in words) in terms of the drug effects on memory. Attach your calculations, the appropriate statistical decisions, and report your findings as would be done for a journal article (e.g. F(4, 25)=4.54, p<.05, h2=.81).

(b) Analyze the data sets you were assigned again, but this time treat it as data from a repeated-measures design. Assume that the experiment is the same but with participants now matched on a variable such as General Intelligence as measured by an intelligence test. Submit your answer on a standard answer sheet, providing details as to statistical test used, null and alternative hypotheses, degrees of freedom, critical values, your calculations and report your decision as would be done in a journal article (e.g. F(4, 21)=5.14, p<.05, h2=.85).